DESCRIPTION: (Applicant's Description) The essential contribution of the Core is the operation, maintenance and development of the Radiological Research Accelerator Facility (RARAF), so that alpha-particles of appropriate energy, at the appropriate dose and dose-rate, are available for the biological projects. The manger of RARAF (Steve Marino) collaborates with the biologists to ensure appropriate irradiation protocols and correct dosimetry. The Core also provides an administrative framework for the ordering of equipment and supplies and the maintenance for accounts. The Bio- Instrument (machine) Shop is a vital need to design and fabricate sophisticated computer-controlled irradiation facility and single-particle beam line. Last but not least, the core presents a vehicle for the exchange of information and ideas, and to coordinate data for publication. The organization structure, consisting of an executive committee and an external advisory committee, is designed to maximize the level of synergy in an integrated effort to accomplish the goals of this program project.